IKVM.NET is a JVM for the Microsoft .NET Framework and Mono. It can both dynamically run Java classes and can be used to convert Java jars into .NET assemblies. It also includes a port of the OpenJDK class libraries to .NET.

reacTIVision is a computer vision framework for the fast and robust tracking of markers attached on physical objects, and the creation of multi-touch surfaces. It was designed for the rapid development of table-based tangible user interfaces.

libdmtx is a software library that enables programs to read and write Data Matrix (or "DataMatrix") 2D barcodes. It runs on several platforms, and can be accessed by multiple languages. The package provides fully featured command line utilities.

This is a collection of Eclipse plug-ins that help you work with .NET. If you used tools like Emonic, this is something that will be helpful. Current functional tools include NUnit and NAnt support. Both tools work like their Java equivalents.

Dr. Micheal Kay: "Saxon 8.7 is the first release to be released simultaneously by Saxonica on the Java and .NET platforms." MDP: Mission accomplished! Saxon for the .NET platform from Saxonica is now available and supported via the http://saxon.sf.net

Part authoring tool, part electronic environment, BrightMOO is designed to demonstrate the feasibility of building client-side, three-dimensional interactive environments using existing MOO technology.

Lightweight cross-platform utility to share the clipboards across multiple computers / platforms in a network (plain text and images). Does not require firewall configuration, or an installation. Just point to a shared folder.

Soar is a general cognitive architecture for developing systems that exhibit intelligent behavior. Researchers all over the world, both from the fields of artificial intelligence and cognitive science, are using Soar for a variety of tasks.